Method of proppant oil or gas formation fracture

ABSTRACT

The invention is related to the field of oil and gas industry, particularly, to the methods of oil or gas formation fracture using proppants, i.e. to the technologies of making fracture cracks, and may be used for underground formations processing, particularly for oil formation fractures. In the method of oil formation fracture including high-rate fluid injection into the formation and addition of a proppant into the fluid, polydicyclopentadiene material is used as the proppant. The method enables ensuring a lower friction during the proppant injection into the well retaining the cracks permeability due to the specific density of the proppant close to 1, its high thermal stability and high crushing strength.

This patent application is a continuation-in-part from U.S. patent application Ser. No. 12/570,838 filed Sep. 30, 2009 which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The invention is related to the field of oil and gas industry, particularly to methods of oil or gas formation fracture using proppants, i.e. to the technologies of making fracture cracks, and may be used for underground formations processing, particularly for oil formation fractures.

Formation fracture is the method used to stimulate production from the reservoir. It consists in the high-rate injection of fluid in the formation which results in the occurrence and propagation of the fracture crack from the well to the reservoir. Fine particles called ‘proppant’ are added to the carrier fluid and carried down the well and then via perforations—into the fracture crack. When the injection stops and the fluid injected flows out through the crack walls, the proppant remains inside the crack thus preventing its full closure. The established high-conductivity channel enables bypassing the well's damaged zones and make a large area of contact with the reservoir.

DISCUSSION OF RELATED ART

Methods of oil or gas formation fracturing using different proppants are known. The possible solutions are stated in the following patents:

-   1. WO2007078995 A1, this Patent discloses a method of filling     fraction cracks using composite proppant particles consisting of     high-strength micro-bubbles and polymer-resin binder. -   2. U.S. Pat. No. 7,281,580, this Patent discloses a method of     creating a partial mono-layer of proppant in the fracture crack     using high-density plastic particles coated with an adhesive. -   3. GB2436011, this Patent discloses underground formation treatment     method including high-rate fluid injection in the oil formation,     adding a proppant to the fluid, as the proppant in this method     polyamide hydraulic fracture and gravel pack proppant. The main     disadvantage of this filter is its low strength.

SUMMARY OF THE INVENTION

The task to be solved through this invention consists in the creation of a simple and efficient method of fracturing an oil or gas formation using a proppant, which is a new type of bulk material with a certain strength and chemical inertness level, for underground formations treatment.

The engineering result attained through the implementation of the solution claimed consists in the lower friction during the proppant injection into the well retaining the crack's good permeability.

Due to the proppant's high density close to 1 it is possible to use lower-viscosity fracture fluids which ensures a lower friction during the injection. The cracks permeability is ensured through a more uniform distribution of the proppant particles along the crack, its high thermal stability and high crushing strength.

The technical tasks set shall be attained through the application of polydicyclopentadiene (hereinafter referred to as polyDCPD) as the proppant in the method of oil or gas formation proppant fracture including high-rate fluid injection and adding the proppant to the fluid. Hereby the polyDCPD particles may have various shapes, e.g., spherical, elongated, polygonal, cubical, they may be made as fibers. The polyDCPD filler may be additionally strengthened using filler, like clay or silicon dioxide, or ceramics, of fibers.

DESCRIPTION

This invention is related to the oil or gas formation fracture including high-rate injection of fluid into the oil or gas formation and adding a proppant to the fluid, using polyDCPD materials as the proppant for underground formations treatment. PolyDCPD proppants may be of various shapes and in various combinations. PolyDCPD material has crushing strength up to 60 MPa and density of about 0.95 . . . 1.03 g/cm³. Therefore polyDCPD particles may be in suspended state and carried by the fracture fluid. The advantage is the fact that the particles' low density enables using less viscous fracture fluids which results in the lower injection friction.

Of all polymers polyDCPD has a unique combination of mechanical, chemical and physical properties which makes it a good alternative to polyethylene, polystyrene, fiber glass, polyether, graphite fiber, aluminum alloys and other materials. PolyDCPD has low density (close to that of water), an excellent combination of rigidity and impact strength; stable dimensions, excellent chemical stability in acids, bases, crude oil, excellent thermal stability; and its mechanical processing is easy.

High-purity polyDCPD Noveon is manufactured by “Telene®DCPD” Company for European and Chinese markets.

PolyDCPD “Metton® PDCPD”, which is basically similar to “Telene®” is manufactured by Metton America Inc. which is going to start mass production as an alternative to fiber glass, wood and metal.

PolyDCPD proppants may have various dimensions, shape and their combinations. Non-spherical proppants may be elongated, protruded, polygonal, cubical, fiber etc. particles. PolyDCPD proppants may be reinforced with suitable fillers, like clay, silicon dioxide, fibers, ceramics etc. 

1. The method of oil or gas formation proppant fracture including injecting high-rate fluid into the oil or gas formation; adding the proppant to the fluid, characterized in the fact that proppant polydicyclopentadiene material is used.
 2. The method of claim 1 characterized in the fact that particles of polydicyclopentadiene may be of various shape.
 3. The method of claim 2 characterized in the fact that particles of polydicyclopentadiene may be elongated and/or polygonal and/or cubical and/or spherical and/or fiber-like.
 4. The method of claim 1 characterized in the fact that polydicyclopentadiene proppant may be reinforced using additional filler.
 5. The method of claim 4 characterized in the fact that the additional filler may be ceramic or silicon dioxide or fiber. 